Douglas P. Wittmer

Thermal effects on electrospray ionization ion mobility spectrometry

A cooled electrospray ionization source was used to introduce liquid sample into an ion mobility spectrometer. This uniquely designed electrospray ionization source eliminated problems encountered in the past when electrospray sources were interfaced to ion mobility spectrometers. Advantages of this electrospray ionization ion mobility instrument included high temperature operation for rapid desolvation of sprayed droplets, prevention of solute precipitation in the spray needle, efficient transmission of ion spray into the spectrometer and complete elimination of corona ionization. Parametric investigations included drift tube temperature, spray needle temperature, solvent flow rate and electrospray voltage. Ion mobility spectra of cytochrome c and poly(ethylene glycol) demonstrated good sensitivity and resolution for high molecular weight compounds sprayed from liquid samples.